1.
contrarian, perverse person, someone who does the opposite
A person who deliberately does or says the opposite of what others expect or want. Common trait in children going through rebellious phases.
あまのじゃくだね。
You're such a contrarian.
Kanji: Written as 天邪鬼 or 天の邪鬼.
Etymology: Originally a small demon of Japanese folklore that reads people's minds and does the opposite of what they want.
Usage: Can function as a noun or na-adjective (あまのじゃくな).
Nuance: Often used affectionately for children who are being deliberately contrary, or self-deprecatingly by adults who recognize this trait in themselves (especially in romantic contexts - people who act cold when they're actually interested).